1. Field of the Disclosure
This disclosure generally relates to an interactive system and, more particularly, to a remote device and a power saving method of an interactive system that perform the object tracking by reading only a part of pixel data of a sensing matrix.
2. Description of the Related Art
The conventional game remote controller, e.g. the one disclosed in Taiwan Patent No. 1267754 and entitled “pointer positioning device of a video camera”, can be applied to a light gun game. The pointer positioning device has a control circuit disposed in a photographic pointing device and coupled to a camera, a calculation unit and a transmission interface respectively. The transmission interface is connected to a host. A filter is disposed in front of the camera and several lighting devices are disposed on a display screen for being captured by the camera. When a user runs the program executed by the host using the photographic pointing device, the camera is used to capture the display screen. And as the camera is integrated with the filter, light outside the spectrum of the lighting devices will be removed such that images captured by the camera only contain the lighting devices. The images are sent to the calculation unit for calculating the coordinate of an aiming point of the camera to be sent to the host, and the host can perform the corresponding control according to the coordinate.
However in practical use, in order to improve the operational convenience, the remote controller communicates with the host via wireless transmission and a battery module is used to provide all power needed by the remote controller. As the remote controller may include a plurality of power consuming devices, it is necessary to reduce the power consumption of each device so as to extend the lifetime of the battery. Generally in order to improve the accuracy of calculating the coordinate of the aiming point, the camera preferably captures images at a higher sampling frequency. However, the high sampling frequency can increase the computing load of the calculation unit such that the total power consumption of the remote controller is increased and the lifetime of the battery is shortened.
Taiwan Patent Publication No. 200912700 discloses a displacement detection apparatus and an energy-efficient method for the same. The displacement detection device is a mouse and includes a light source and an image capturing unit, wherein the image capturing unit is configured to successively capture images of a surface to which the light source projects light. The displacement detection device calculates a position difference of the reference object in the captured images so as to obtain a motion vector. When the motion vector is smaller than a threshold with a predetermined time, the displacement detection device is identified to operate in an idle state rather than in an operating state. If the displacement detection device is in the idle state, a lighting frequency of the light source is decreased so as to reduce the power consumption. Similarly, Taiwan Patent Publication No. 200943131 discloses a motion estimation device and a power saving method thereof that may adjust a lighting cycle of the light source according to the displacement of the motion estimation device between two successive lighting durations of the light source so as to reduce the power consumption.
Different from subjects of the above two published specifications regarding the mouse, Taiwan Patent No. 1338241 discloses an interactive image system, an interactive device and an operative method thereof that may real-timely adjust a sampling frequency of an image module in the interactive device so as to reduce the power consumption thereof. The methods of reducing the sampling frequency of the image module or the lighting frequency of the light source mentioned in the prior art are all performed by retrieving and processing image data of the whole image frame, and thus the power consumption can not be effectively reduced.
Other related patents may be referred to the U.S. Pat. No. 7,839,388, U.S. Pat. No. 7,738,013, U.S. Pat. No. 7,619,669 and the U.S. Patent Publication No. US 2007/0024587.
Accordingly, the present disclosure further provides a remote device and a power saving method of an interactive system that may select to read only a part of pixel data of a sensing matrix according to an image feature of the reference beacon image thereby reducing the total power consumption of the image sensing device.